Prevention of substantial corrosion in hydrocarbon-oil-treating apparatus



May 28, 1929. .1. c. MORRELL ET AL PREVENTION OF SUBSTANTIAL CORROSIONIN HYDROCARBON OIL TREATING APPARATUS Filed Sept. 3, 1925 JabqaeC/ldorrell attozueg Patented May 28, 1929.

UNITED STATES 'PAT'ENT' OFFICE.

JACQUE C. MORRELL AND HARRY BENNER, OF CHICAGO, ILLINOIS, ASSIGNORS TOTHE UNIVERSAL OIL PRODUCTS COMPANY, OI CHICAGO, ILLINOIS, A CORPORA-TION OF SOUTH DAKOTA.

PREVENTION OF SUBSTANTIAL coanosron m HYDROCARBON-OIL-TREATINGAPPARATUS.

Application filed September 3, 1925. Serial No. 54,340.

This invention relates to improvements in a method of preventingsubstantial corrosion in apparatus for treating hydrocarbon oils,

and refers more particularly to the idea of introducing ammoniumhydroxide or a solution of ammonia in water into the oil treatingapparatus at a point where condensation of water would take place.

More specifically this process has for its purpose the prevention ofcorrosion in vaporlines and condenser tubes of hydrocarbon oil treatingapparatus. This corrosion is formed by the hydrochloric acid producedduring the reaction in the apparatus when treating hydrocarbon oilswhich contain chlorides, especially those of magnesium and calcium.

The hydrocarbon oils which generally contain chlorides may be naturallyoccurring emulsified oils, although it is to be understood that theinvention contemplates broadly the prevention of corrosion formed by anyoils, whether emulsified or not, which contain chlorides.

Crude oils and other heavy oils which contain water emulsified therein,usually have various salts dissolved in the water which on heating ordistillation form hydrochloric acid by hydrolysis. This is true whetherthe emulsified oil has been previously treated to remove a certainportion of the water or not.

In carrying out the present invention a solution of ammonia in water,forming ammonium hydroxide is injected into the apparatus at a pointwhere condensation of the water will take place, for instance in thecondenser. The ammonia solution neutralizes the hydrochloric acid formedin the apparatus as previously described. Further this solution ofammonia not only neutralizes the hydrochloric acid,- but also dilutes itowing to the excess Water. It will thus be seen that the double actionof neutralization and dilution taking place gives ,the maximumprotection against the effects of the hydrochloric acid and therebyprevents excessive corrosion. The ammonium chloride formed as a resultof neutralization remains dissolved in the water and is carried awaytherewith.

The single figure of the accompanying drawing illustrates a sideelevational view of an apparatus by which the process according to thepresent invention may be carried out.

' The illustrated embodiment of the apparatus comprises a heating coil1, an enlarged reaction chamber 2, a dephlegmator 3, a condenser 4, anda receiver 5, serially connected. Suitable connections are provided forintroducing the raw oil to the heating coil 1, and

to return reflux condensate from the dephlegmator 3 to the heating coil.The ammonia solution may be introduced to the pipe 7, which conducts thevapors from the dephlegmator, 3 to the cooling coil 4, by means of apipe 8 controlled by a valve 9.

In actual practice it has been found that the use of the presentinvention prevents substantial corrosion to such an extent that where itwasnecessary formerly to renew tubes or piping say every threeor fourdays, that utilizing the present invention it isnow only necessary torenew the same piping about every thirty days, more or less.

As an example of carrying out the present invention in actual practice,the distillation and cracking of Smackover crude may be cited. The crudecontains say 2% of salt water, the salt being composed of magnesium andcalcium chlorides which form hydrochloric acid on heating.

' By analysis, it was estimated that 2% to 1% solution of ammonia wouldcompletely neutralize the hydrochloric acid. Fifty gallons per hour ofthis solution cut downthe corrosion by neutralization and dilution to apoint where it was feasible to operate over long periods as describedabove without difficulty. It is, of course, recognized that any amountof hydrochloric acid can be neutralized by adding a large quantity. andhigh enough concentration of ammonia solution.

The above figures and proportions are purely illustrative, and we do notin any way wish to limit ourselves to such proportions. I

It was found'that the introduction of large quantities of ammoniasolution per hour into the oil treating apparatus, operating underpressure, did not affect the operation of the process at all.

We are awarethat gaseous ammonia has been introduced into an oildistilling apparatus at substantially atmos heric ressure.

One of the advantages 0 intro ucin a solution of ammonia rather thansome ot er alkaline substance, is that the ammonia vaporizes from thesolution, which neutralizes an hydrochloric acid in the vapors which 0not come in contact with the aim monia solution.

We claim as our invention:

1. A method for preventing corrosion of the condensing portion of an oilcracking apparatus, consisting in introducing ammonia in solution to thevapors subsequent to the heat treatment thereof and prior to theirpassage through the condensing portion of the apparatus whereby theammonia solution is not subjected to the oil cracking conditions, toeffect a neutralization of the hydrochloric acid contained in the vaporsformed during the cracking reaction in the apparatus.

2. A method for preventing corrosion of the condensing portion of an oilcracking apparatus, in which hydrocarbon oils are converted undersuperatmospheric pressure, consisting in introducing and mixing with thevapors, subsequent to the cracking reaction and prior to finalcondensation, regu lated quantities of ammonia in solution,

adapted to neutralize and dilute any hydrochloric acid formed during thecracking reaction without subjecting said ammonia'solution to thecracking treatment for the oil.

J ACQUE C. MORRELL; HARRY P. BENNER.

